We knew what was up. So did he. The Thunder let one slip away Sunday night, let a chance to take control of the NBA Finals fall right through their hands ... and off the rim ... and into the laps of 3-point shooters they kept fouling.

"We've just got to make sure we realize that we're all in the Finals," said Perkins, who's been here before and knows what was squandered in Game 3. The Thunder lost the game, 91-85, allowing the Heat to take a 2-1 lead in the best-of-7 series, but they lost so much more than that.

"Guys might not get this chance ever again in their life," Perkins said. "You've got to take advantage of it."

In the third quarter, the Thunder managed to build a 10-point lead despite Kevin Durant being on the bench with four fouls. Despite it all, despite LeBron James' ongoing and ruthless assault of the paint in this series, they found themselves trailing by a single point, 86-85, with 90 seconds left. Both times, they melted.

They turned the ball over. They couldn't make a shot, from the field or from the free-throw line, where the best foul-shooting team in the regular season (81 percent) shot 15-for-24 (63 percent).

Worse, they committed dumb fouls -- consecutively fouling 3-point shooters Shane Battier and James Jones, who made all six foul shots, late in the third -- and "touch" fouls. Those were Perkins' words -- Perkins who came from the "no-layup" Celtics, speaking after the Thunder allowed a parade of layups that rivaled the victory parade the Heat treated themselves to in July 2010, when the Big Three were formed.

The moment, a one-point game on the road in the Finals against a team they needed to push into a clutch moment to see how it would respond, demanded so much more than that. The Heat were never pushed, never had to make a pressure shot, never had to feel the burden of falling into a 2-1 hole on their home floor, because the Thunder let them off the hook.

"You've got to understand that over there in the other locker room, there's a team that really wants it," Perkins said. "You've got a couple of guys that want it; they want this. So nothing's going to be given to us. We've got to go take it."

The Thunder had been down 0-2 to the great Spurs of San Antonio, and didn't flinch. They'd toppled the Lakers and the Mavericks, too; champions, all. It was as difficult a road to the Finals as a young team could take, and their response to pressure in these playoffs did not suggest the kind of meltdown we saw from them Sunday night.

"We did some things that cost ourselves an opportunity to win this game," Derek Fisher said.

Too many mistakes. Too much "hero ball," Perkins said.

"I thought we got back to ‘I' basketball -- individual, contested looks all night, shooting over two and three people," Perkins said. "They'll live with that shot. But if we make them rotate and we make the extra pass, it's night and day.

"Hero ball is exactly what we were playing tonight," Perkins said.

For the first time in the series, the Thunder avoided the slow starts that have plagued them, managing not to fall behind by double-digits in the first quarter. But they still had no answer for James' determined assault on the paint, nor did they have the poise to force James or Dwyane Wade to make contested jumpers under pressure with the game on the line. The Heat are determined to draw from the experience of last year's failure in the Finals, but weren't forced to dig too deeply into that archive Sunday night.

"We talk about it all the time," said James, who had 29 points and 14 rebounds. "We understand that it's been a great teacher for us, just the experience. We don't take things for granted."

The Thunder took too much for granted in Game 3, left too much to chance.

Durant went to the bench after being called for his fourth foul with 5:41 left in the third and the Thunder leading 60-54. On the bench he stayed for the rest of the quarter, along with Russell Westbrook, who was yanked by coach Scott Brooks with 5:01 left after a series of mistakes. The Thunder went 1-for-10 from the field the rest of the quarter, and the Heat led 69-67.

There was a tendency to blame the officiating -- this is the NBA, after all, where everybody blames the officiating -- but that's not how Perkins saw it. That's not how I saw it, either.

"He's got to be smarter," Perkins said of Durant. "Some of them were fouls. The charge [committed by Durant on a three-point play by James with 3:44 left in the fourth] was questionable, but at the end of the day, you've got to be smarter."

Spoken like a guy who has won and lost in the Finals before and knows that asking the refs to call fouls or not call them can't be your best strategy in this setting, at this time of year.

The Thunder's ultimate undoing, however, came in waves of incompetence and anxiety in the fourth. Their downfall started innocently enough with Chris Bosh's block of Durant's driving jumper, which was followed by a missed 3-pointer by Durant and two straight turnovers by James Harden. Then came the three-point play by James, who blew up Durant on his way to the basket to draw the and-one. Block, charge, whatever. The Thunder's mistakes ensured that James could simply do what he does best -- run the floor and overpower everyone in his path. Suddenly, a one-point game had become an 84-77 lead for the Heat with 3:44 left.

Then, the final 90 seconds -- a horror show for the Thunder, a team that had stood up to the Spurs but hadn't grown up enough to make the Heat earn their first home game in this series.

Westbrook had made a 17-footer to cut Miami's lead to 86-85 with 1:30 left, and that was the last time the ball would go through the basket for Oklahoma City. Durant missed a jumper, Westbrook missed a 3-pointer, and then Harden tried to draw a charge from James. OK, he flopped. That's what he did, and the irony for the Thunder is that if Harden hadn't hit the deck, the whistle probably wouldn't have blown.

James hit 1 of 2 from the line, his 29th and final point -- the final point that was necessary from him, because Thabo Sefolosha's lazy inbounds pass was stolen by Wade with 16 seconds left.

"After the game, everybody should say, 'I did everything I was supposed to do, everything I can do, I played my heart out,' and then you live with the results," Perkins said. "If you lose, you lose. But you shouldn't have any regrets."

Before joining CBSSports.com, Ken Berger covered the NBA for Newsday. The Long Island, N.Y., native has also worked for the Associated Press and can be seen on SportsNet New York. Catch Ken every Saturday, when he hosts Eye on Basketball from 6-8 p.m. ET on cbssportsradio.com